Background. Currently, there is insufficient data in the literature on the relationship between insulin resistance and body composition in elderly patients with type 2 diabetes mellitus (DM2). Aim: evaluate the relationship between body composition and insulin resistance in elderly patients with DM2. Materials and methods. The simultaneous cross-sectional study included 488 elderly patients with DM2 (268 men and 220 women), divided into four groups: patients with normal body composition, with sarcopenic obesity (SO), obesity, and sarcopenia. All participants were collected complaints, medical history, life history, measurement of anthropometric data (height, body weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), WC/HC ratio). Blood pressure was measured in all patients, fasting blood plasma glucose and C-peptide levels, ALT, AST, uric acid concentration, glycated hemoglobin (HbA1c), and serum lipid profile were determined. The study of the compositional composition of the body was carried out by the bioimpedance method. Results: the incidence of SO in the study participants was 14.5% (11.9% in men and 17.7% in women). Insulin resistance, estimated using the homeostasis model (HOMA2-IR), was higher in the SO group than in the obese group (p = 0.045), and was also significantly higher in the SO or obese groups, compared with the groups of participants with normal body composition or sarcopenia (p